Another question about ECAD work and who does what

This is slightly different than my post about using the wire harness module. For those who have engineering staffs with electrical and mechanical engineers and are using ECAD, can you give me some insight into how the work is divided up? In our company, we generate block diagrams, schematics, wire harness drawings, and assembly drawings that show the wire harnesses in the machines.

Are you dividing this work up between the electrical and mechanical engineers? If so, who is handling what?

Currently, our electrical engineers are using some type of free schematic program. A machine prototype is wired up based on the schematic. That information is give to me and I create the various wire harness drawings in SE draft and create a BOM with various connectors, wire lengths, strip lengths, wire numbers etc. Then I have to roughly sketch the representation of the wire routing using draw-in-view in the assembly drawings. Finally, I create a better looking schematic with an overall block diagram and 2D views of the actual components and using the connector tool in SE draft.

This is horribly inefficient and requires replicating work several times. The bulk of this work is handled by me and I seem to spend way more time documenting the electrical aspects of our machines than I do the mechanical.

Purchasing an ECAD system and adding the wire harness module to SE will be an expensive undertaking, but I'm thinkg that our current method is somewhat crude and not sustainable for expansion.

One thought I have is to use the free SE 2D draft program and have the electrical engineers handle the schematics

Re: Another question about ECAD work and who does what

Here at my work we are heavily reliant on creating drawings for manufacture. The mechanical engineers are doing the bulk of the documentation work, except for the generation of Gerber files for the PCB manufacture. Usually the EEs dump out dxfs of their layouts and it is up to the mechanical engineers to model the components and place them on the boards based on overlaying a dxf on the board model using sketch. Once the assembly is made we can do the assembly drawings and generate the parts lists. This is inefficient also, but we are kind of stuck with it, because our EEs are using a low end ECAD system that is actually on a Macintosh platform. MEs are also responsible for making schematic drawings, but we usually just get a JPG out of the EEs ECAD system and embed that in our drawing borders. The actual mechanical drawing of any wiring is also left up to the MEs. Probably not the best scenario, but it works. We have also started playing around with dumping out STEP files out of the ECAD package. We haven't fully zeroed in on this process yet, and it requires that the MEs first generate accurate models of the componets to give to the EEs to use in the ECAD system via a STEP file. It does look promising though.

Re: Another question about ECAD work and who does what

OK. This is how I help setup or harness design strategy at a global manufacture I worked for. Granted this was over 10 years ago and it was using NX. With that said the process is a process.

1. We developed complete assemblies. No leaving out of hardware. Our assemblies were quite large and consisted of several different configurations (gas engines, LP engines and electric/battery).

2. Electrical was owned by the EE department and we had a dedicated harness designer

3. Hydraulics and pnumatics had a dedicated group as well.

4. Mechanical engineering owned the overall assembly and the project engineer was responsible for the quality of the assembly. This was through development phases. Current engineering group was responsible for the assembly data after release to production.

5. Mechanical chose the components and those components would be allocated to the mechanical system they belonged to. The components would have to be created and then pushed to Electrical or Hyd/Pnu engineers for routing information to be added to the models.

6. Each group had their own top level assembly and were responsible for the quality of the data it contained.

7. EE group would output HRN and CMP lists

8. harness designer would then import that in NX routing and start running the harness design- inside the electrical assembly. There would be the main harness and then secondary harness.

9. Harness designer would then generate the form board drawings with pin connector id and wire locations.

The same process applied to the Hyd/Pnu group as well.

Once Siemens PLM completes their purchase of Mentor Graphics we should start to see some great integrations coming our way!

Re: Another question about ECAD work and who does what

So I'm back revising schematics again and spending a lot of time doing so. In addition to schematics and wire harness drawings, the issue I run into is how to show the harness in the 3D model and then have a representation show up in the assembly drawing. The wire harness module seems like the best way to go. I spend too much time trying to "fudge" some representation of the wires into the harness. Also, in doing that, I don't have a good BOM representation unless I create empty files to serve as placeholders.

Re: Another question about ECAD work and who does what

I am doing harness routing drawings and went down the 3D sketch route in an assembly.

I didn't need every individual route as the drawings are only to show what goes where and how it gets there, so one line can represent several harnesses. For the BOM I just add the lines manually.

I can tell you now, the 3D sketch method has been a complete nightmare and I would have been better off using XpresRoute and creating solid 'tubes' for every harness. At first I tried this but without creating a physical tube - unfortunately I couldn't get the path to display in a drawing. It's the same with frames - you can't display the frame paths without a physical frame.

3D sketches can be VERY difficult to manipulate - things like adding a fillet between 2 lines only works if the end points are connected (I think), you can't fillet one line to another, then the same one to another line. (2D fillet just extends lines as required), lines drift off into space unless they are absolutely nailed down.

I've even had completely unrelated lines go astray when another is modified.